Where Do All the Toxins Go? (External View)

Transcription

1 Toxic Chemicals in the Great Lakes 2 of Two Activities Where Do All the Toxins Go? (External View) Bioaccumulation is the build-up of chemicals in an organism s body the longer an organism lives, the more it absorbs. When an older, large lake trout is caught, the concentration of toxins in its body could be a million times that of the original concentrations in the water. Biomagnification results when toxins become increasingly concentrated as they pass through the food chain. When a fish feeds on zooplankton, for example, the fish takes up toxins in all of the plankton it eats. In the fish, many of the toxins accumulate in its fatty tissues. When a gull or an eagle feeds on the fish, the bird takes up all of the toxins the fish has accumulated from all the contaminated organisms it has ever eaten. Therefore, the higher up an organism is in the food chain, the greater the amount of toxins it is likely to consume. Earth Systems Understandings This activity addresses ESU 2 (stewardship), 3 (science processes), and 4 (interactions). Materials Each group will need: Copy of Table 1. Copy of human activities and industry cards (1 page). 1 toxin card. Copy of food chain cards (3 pages). Copy of effects of toxin cards (1 page). Scissors. Posterboard or butcher paper. Glue. Municipal waste incinerator Objectives When you have completed this activity, you should be able to describe how bioaccumulation and biomagnification of toxins in the food chain cause health disorders in humans and animals. Procedure 1. The teacher has prepared cards for the teams. Each of the eight themes (fish, mammals, etc.) is on a different color. 2. Work in groups of three to four people to make a poster. First assemble a reasonable food chain from the cards you have. 3. Each group will be given one toxin card and all of the other cards in order to trace the toxin from its origin to its effects in humans and/or other animals. Table 1 will provide source and effect information on the toxins. Mercury Mayfly Nymph 4. Have each group show its food chain poster to the class, and explain the interactions they have linked together. Humans Lake trout Bald Eagle Brain damage in humans Damage to human nervous system and liver Death in fish and wildlife Issues G115

2 Table 1. Toxins Source and Effect Information. Review Questions 1. With the use of the constructed food chain, explain what bioaccumulation and magnification are and how these factors cause health disorders in humans and animals. 2. List and explain different types of human activities that produce airborne toxins and what effects these toxins have on humans and animals. Extensions 1. Look up information on the percentages of toxins found in the Great Lakes that probably reached there on air currents. Use your maps to determine where these toxins may be originating. 2. Do a study on how incinerators work and how they are regulated. 3. Choose a city and discuss the human health effects that might be found in its residents as a result of the airborne pollutants. Answers to Review Questions 1. Varies by choice of toxin. 2. Refer to Chart 1 in Activity A of this section and Table 1 of Activity C, which is on this page. Teacher s Note A public health advisory chart, which indicates the fish that are considered dangerous to eat, is included with the activity "Which fish can we eat?" These restrictions are a reflection of the bioaccumulation of toxins in those fish. G116

3 References Eisenreich, Steven J Toxic Fallout in the Great Lakes. Issues in Science and Technology. Fall Fortner, Rosanne W. and Victor Mayer, eds. The Great Lake Erie Columbus: Ohio Sea Grant College Program. pp Hall, Bob and Mary Lee Kerr Green Index: A State-By-State Guide to the Nation s Environmental Health. Washington D.C.: Island Press. pp Hilleman, B The Great Lakes cleanup effort. Chemical and Engineering News 66(6): Michigan Department of Natural Resources 1992 Michigan Fishing Guide. Ohio Sea Grant College Program, PCBs: Their history and our health. Fact Sheet #007. Sierra Club, Sweet Water, Bitter Rain: Toxic Air Pollution in the Great Lakes Basin. A 1988 Update, Lake Michigan Federation. G117

4 Toxins DDT PCBs Toxins Dioxins Toxaphene Toxins Mercury Lead Toxins Arsenic Benzopyrene Toxins Effects of Toxins Hexachlorobenzene Human Cancers Dieldrin Brain Damage in Humans G118

5 Plants & Phytoplankton Plants & Phytoplankton Plants & Phytoplankton Effects of Toxins Effects of Toxins Effects of Toxins Tumors in Fish Death in Fish and Wildlife Human Illness Cattails Water Lilies Rice Cutgrass Birth Defects in Humans Damage to Human Nervous System & Liver Livestock Mortality Blue-Green Algae Duckweed Purple Loosestrife G119

6 Food Chain: Birds Mallard Duck Bald Eagle Food Chain: Birds Seagull Blue Heron Food Chain: Birds Red-Tailed Hawk Blue-Winged Teal Duck Food Chain: Fish Lake Trout Yellow Perch Food Chain: Fish Coho Salmon Walleye Food Chain: Fish Catfish Alewives G120

7 Food Chain: Mollusks, Insect Larvae and Zooplankton Caddisfly Snails Food Chain: Mollusks, Insect Larvae and Zooplankton Zebra Mussels Daphnia (Zooplankton) Food Chain: Mollusks, Insect Larvae and Zooplankton Mayfly Nymph Freshwater Clams Food Chain: Mammals Food Chain: Mammals Food Chain: Mammals Mice Red Fox Rabbit Beaver Raccoon Muskrat G121

8 Food Chain: Mammals Human Incinerators and Boilers Copper Smelters Sewage Incineration Manufacture of Chlorinated Solvents Pulp and Paper Mills Production of Glass Cigarette Smoking Application of Agricultural Pesticides Use of Leaded Fuels Coal Combustion G122